This invention relates to an electronic control apparatus for controlling ignition timing of a V-type multi-cylinder internal combustion engine.
In a V-type multi-cylinder internal combustion engine, camshafts are respectively provided inside each cylinder head of right and left banks and each the camshaft is driven by a timing belt from a crankshaft, and also crank angle detecting means is provided in either one of the camshafts and ignition timing is controlled by a rotational angle signal of this crank angle detecting means. Since the timing belt has some looseness and has rotational resistance caused by reaction force of a valve spring to a lift of an intake valve or an exhaust valve applied to the camshafts, however, the crankshaft cannot rotate in perfect synchronism with the camshaft and a deviation occurs between the rotational angle signal of the crank angle detecting means and the actual rotational angle of the crankshaft due to variations in angular velocity in rotation of the camshaft, with the result that the ignition timing has deviated from normal ignition timing.
As a technique for correcting such a deviation of the ignition timing, one example is disclosed in the Unexamined Japanese Patent Application Publication no. Hei 3-18666. This technique notes that the ignition timing of the bank of the side in which the crank angle detecting means is provided delays to that of the bank of the other side, and is configured so that the crank angle detecting means determines whether there is ignition in either side and for the bank of the side in which the crank angle detecting means is not provided, the ignition timing is set by output of the crank angle detecting means and for the bank of the side in which the crank angle detecting means is provided, the ignition timing is corrected by a correction table map using a rotational speed and a advance angle correction value as parameters.
Also, a technique regarding correction of the ignition timing in case that variations have occurred in angular velocity of a camshaft is disclosed in the Examined Japanese Patent Application Publication No. Sho 58-51155 though the technique is not a case of an ignition apparatus for a V-type multi-cylinder internal combustion engine. This technique is configured so that when the ignition timing according to a rotational speed is set, the next signal period is calculated and predicted from the previous and this signal periods of crank angle detecting means and by calculating an angle from a first reference position signal placed in the maximum advance angle position, ignition at the calculated angle is set and also, a second reference position signal is provided in a top dead point position and in case that ignition by the calculation has delayed due to occurrence of sudden change in the angular velocity, ignition is forcedly performed by this second reference position signal and trouble caused by delay of the ignition timing is avoided.
In the conventional apparatus as described above, the former is that the correction table map is used to correct a deviation of ignition timing between the respective right and left banks. Since these is correction based on the ignition timing of one bank, the deviation of ignition timing between the banks can be corrected, but a deviation of an absolute angle between a camshaft and a crankshaft resulting from variations in angular velocity of the camshaft cannot be corrected and thus, it was difficult to obtain proper ignition timing to a rotational angle of the crankshaft. Also, since the latter technique predicts a difference between the previous and this signal periods of the crank angle detecting means as a difference between the next and this periods as it is, the deviation of the absolute angle between the camshaft and the crankshaft resulting from the variations in angular velocity of the camshaft cannot still be corrected, with the result that an error occurred in the next predicted period due to the deviation between the previous and this periods caused by the deviation of angle and a deviation of the ignition timing also occurred.
The invention is implemented to solve such problems, and it is an object of the invention to obtain an electronic control apparatus of an internal combustion engine for ignition timing control capable of controlling accurate ignition timing even in case that a difference in angle occurs between a crankshaft and a camshaft and an angle error occurs in output of crank angle detecting means in a V-type multi-cylinder internal combustion engine.
An electronic control apparatus of an internal combustion engine according to the invention comprises a V-type multi-cylinder internal combustion engine having right and left banks, crank angle detecting means which is provided in a camshaft of one of the right and left banks of this internal combustion engine and outputs a rotational angle signal, cylinder determination means for generating a determination signal of cylinders to be ignited of the internal combustion engine, intake air volume measuring means for measuring an intake air volume of the internal combustion engine, and an ECU for inputting at least the intake air volume, the rotational angle signal and the cylinder determination signal to calculate a rotational speed and ignition timing, and it is configured so that this ECU calculates a signal period from the rotational angle signal of the crank angle detecting means and predicts to calculate a signal period of the next time from a state of change in the signal period of the same bank and sets ignition timing of the next time based on this predicted result.
Also, the electronic control apparatus comprises a V-type multi-cylinder internal combustion engine having right and left banks, crank angle detecting means which is provided in a camshaft of one of the right and left banks of this internal combustion engine and outputs a rotational angle signal, cylinder determination means for generating a determination signal of cylinders to be ignited of the internal combustion engine, intake air volume measuring means for measuring an intake air volume of the internal combustion engine, and an ECU for inputting at least the intake air volume, the rotational angle signal and the cylinder determination signal to calculate a rotational speed and ignition timing, and it is configured so that this ECU calculates a signal period from the rotational angle signal of the crank angle detecting means and predicts to calculate a signal period of the next time of the other bank from a state of change in the signal period of one bank and the signal period of the previous time of the other bank and sets ignition timing based on this predicted result.
Further, map retrieval of a correction amount of a rotational angle signal position is performed by at least one of the rotational speed and charging efficiency calculated from the rotational speed and the intake air volume and the ignition timing is corrected by this correction amount.
Furthermore, a deviation of the signal period between the banks is calculated from the signal period of one bank and the signal period of the other bank and the correction amount is calculated from this deviation to correct the ignition timing.
In addition, a plurality of rotational speed ranges are set and the correction amount of the ignition timing is set every the rotational speed range.
Further, the electronic control apparatus comprises a V-type multi-cylinder internal combustion engine having right and left banks, crank angle detecting means which is provided in a camshaft of one of the right and left banks of this internal combustion engine and outputs a rotational angle signal, a misfire sensor which is provided in a crankshaft of the internal combustion engine and outputs a rotational angle signal, cylinder determination means for generating a determination signal of cylinders to be ignited of the internal combustion engine, intake air volume measuring means for measuring an intake air volume of the internal combustion engine, and an ECU for inputting at least the intake air volume, the rotational angle signal and the cylinder determination signal to calculate a rotational speed and ignition timing, and it is configured so that this ECU calculates a signal period from the rotational angle signal of the crank angle detecting means and predicts to calculate a signal period of the next time from a state of change in this signal period and sets ignition timing and also calculates a correction amount from a deviation between a rotational angle signal position obtained from the crank angle detecting means and a rotational angle signal position obtained from the misfire sensor and corrects the ignition timing by this correction amount.
Moreover, it is configured so that ignition is turned on according to a particular angle signal of the crank angle detecting means when it is determined that change in the signal period corresponding to each the bank exceeds a predetermined value from the calculated result of the signal period.
Also, the electronic control apparatus comprises a V-type multi-cylinder internal combustion engine having right and left banks, crank angle detecting means which is provided in a camshaft of one of the right and left banks of this internal combustion engine and outputs a rotational angle signal, a misfire sensor which is provided in a crankshaft of the internal combustion engine and outputs a rotational angle signal, cylinder determination means for generating a determination signal of cylinders to be ignited of the internal combustion engine, intake air volume measuring means for measuring an intake air volume of the internal combustion engine, and an ECU for inputting at least the intake air volume, the rotational angle signal and the cylinder determination signal to calculate a rotational speed and ignition timing, and it is configured so that this ECU calculates a signal period from the rotational angle signal of the crank angle detecting means and predicts to calculate a signal period of the next time from a state of change in this signal period and also stores a rotation area in which change in the rotational angle signal by the crank angle detecting means becomes large and predicts to calculate a signal period of the next time from a state of change in the signal period by the rotational angle signal of the misfire sensor within this rotation area and sets ignition timing of the next time based on these predicted results.
Further, the rotational speed for deciding the ignition timing is calculated from a plurality of signal periods.